Development of a Reverse Logistics Modeling for End-of-Life Lithium-Ion Batteries and Its Impact on Recycling Viability — A Case Study to Support End-of-Life Electric Vehicle Battery Strategy in Canada

The deployment of a sustainable recycling network for electric vehicle batteries requires the development of an infrastructure to collect and deliver batteries to several locations from which they can be transported to companies for repurposing or recycling. This infrastructure is still not yet developed in North America, and consequently, spent electric vehicle batteries in Canada are dispersed throughout the country. The purpose of this reverse logistics study is to develop a spatial modeling framework to identify the optimal locations of battery pack dismantling hubs and recycling processing facilities in Canada and quantify the environmental and economic impacts of the supporting infrastructure network for electric vehicle lithium-ion battery end-of-life management. The model integrates the geographic information system, material flow analysis for estimating the availability of spent battery stocks, and the life cycle assessment approach to assess the environmental impact. To minimize the costs and greenhouse gas emission intensity, three regional recycling clusters, including dismantling hubs, recycling processing, and scrap metal smelting facilities, were identified. These three clusters will have the capacity to satisfy the annual flow of disposed batteries. The Quebec–Maritimes cluster presents the lowest payload distance, life-cycle carbon footprint, and truck transportation costs than the Ontario and British Columbia–Prairies clusters. Access to end-of-life batteries not only makes the battery supply chain circular, but also provides incentives for establishing recycling facilities. The average costs and carbon intensity of recycled cathode raw materials are CAD 1.29/kg of the spent battery pack and 0.7 kg CO2e/kg of the spent battery pack, respectively, which were estimated based on the optimization of the transportation distances.


S1.
New zero-emissions electric vehicles registrations Statistics Canada provides data for annual registrations of new EVs purchased in Canada by province from 2011 to 2021 (Table S1), including full battery electric vehicles (BEVs), hybrid electric vehicles (HEV), and plug-in hybrid electric vehicles (PHEVs). ZEVs include BEVs and PHEVs. Conventional Hybrid EVs are not considered as they don't use LIBs [1]. Table S1: Annual new electric vehicle registrations [2] (1) Data for Newfoundland and Labrador, Nova Scotia and Alberta are currently not available due to contractual limitations of the existing data sharing agreement.

S2.
Baseline MFA scenario for EV LIBs The forecast for the baseline scenario is based on the extrapolated annual number of passenger vehicle sales resulting from a 6% retirement rate of passenger vehicle stock estimated in the C.D. Howe study [3], and a 1-percentage point increase of the annual share of ZEVs in total light-duty vehicle sales based on the historic values from 2018 to 2021. Table S2 shows the Baseline MFA scenario for EV LIBs.

Battery mass allocation among Canadian provinces
Note that available spent EV LIB mass per each province can be estimated by assuming an average of 326 kg per battery pack (Table S4 and Table S5).  S5.

Workflow for the allocation of battery mass among collections sites in population centers
This workflow consists of the following tasks: Filter PCs for each provincial cluster by using definition query and the Near geoprocessing tool with a geodesic method to remove all PCs that are classified as small PCs with a population between 1,000 and 29,999 and that do not have a collection site either within them or within 30 km outside of their borders. (ii) Connect collection sites to their PCs by using the Spatial Join geoprocessing tool, which finds the closest PC for each collection site (as long as it is within 30 km) and joins its attributes one to one. (iii) Filter additional PCs by using the Summary Statistics tool to count the number of collection sites associated with each PC. Remove additional PCs without collection sites associated with them. (iv) Weighted allocation of total provincial battery mass between selected PCs is based on the number of households with an income over CAD 100,000 per PC, which are estimated by using the Enrich tool and Business Analyst data source.
The allocation of PC's spent battery pack mass between individual scrapyards is obtained by using the Join Field tool, which connects each collection site with the population center associated with it, to calculate the battery mass for each collection site by dividing total battery mass assigned to each PC between the total number of collection sites associated with it.

S8. Dismantling and recycling facilities candidates
The location of dismantling and recycling facilities candidates is assumed to be industrial zones, which are preferably placed up to 15 km from cities centroids in most major Canadian cities. Facilities candidates are located in 59 medium and large urban population centers, with a population of 50,000 or more. The initial selection of dismantling hub locations can be filtered to those inside or within 30 km from large urban population centers, and a preferred distance of recycling processing facilities candidates from rail stations is set up as 5 km that may facilitate shipments to battery production facilities (Table S6).

Smelting facilities candidates
There are 10 primary aluminum smelters in Canada: one is located in Kitimat, British Columbia, and the other nine are in Quebec. There is also one alumina refinery located in Jonquiè re, Quebec [5]. Steel smelters are distributed along many Canadian provinces. Regarding copper smelters in Canada, Glencore's Horne Smelter in Rouyn-Noranda is now the only copper smelter in Canada as, from 2015 to 2018, Vale's Copper Cliff Sudbury smelter was converted to process nickel concentrate (Table S7). The Horne Smelter in Rouyn-Noranda is a custom copper smelter which uses both copper concentrates and precious metal-bearing recyclable materials as its feedstock to produce a 99.1% copper anode. The Horne smelter has a total reported processing capacity of 840,000 tonnes/year (Glencore) [6]. It is important to note that this study does not consider transportation of waste batteries outside of Canada. Due to the lack of copper smelters in the West cluster, this study assumes that copper scrap from dismantling facilities is stockpiled as waste and is not shipped to overseas smelting facilities. For instance, the metal concentrates from the Teck Resources' Highland Valley Copper facility in Trail, BC are processed and then are all exported, where the majority is sold under long-term sales contracts to overseas smelters.  Table S8 presents the aggregated truck transportation distance of each reverse logistics segment for each regional recycling cluster expressed in terms of ton-kilometers (t·km).

S11. Life cycle GHG emissions and transportation costs
This study used a gate-to-gate approach, which means the starting point of the LCA's system boundary for the transportation of spent batteries is the collection site, and the end of the assessment is at the recycling processing facility. The recycling processing facilities include battery cell recycling processing and other battery pack metals recovery facilities. The life cycle GHG emissions are calculated by multiplying an average GHG emissions factor for truck transportation by the travel distance for each segment route. This study uses the LCA software tool openLCA v.1.10.3. It has a feature to integrate third-party databases such as Ecoinvent v. 3.7.1., which is used as a data source to provide a GHG emissions factor for trucking transportation. The transportation process dataset in Ecoinvent to be used in this study is named "Transport, freight, lorry 16-32 metric ton, EURO3, t·km, ROW". The sub-processes included in this dataset are lorry production, operation, maintenance, road construction, operation and maintenance. The life cycle impact assessment of freight transportation by truck was assigned to the impact category: climate change as global warming potential (GWP) over a time period of 100 years and presented with respect to the functional unit of kg CO2e per kg of spent battery pack. The emission intensity of trucks on transportation networks for the functional unit 1 ton-km for the GWP impact category is 0.17276 kg CO2e/t·km and is evaluated with the method ReCiPe 2016 Midpoint (H). The data regarding the distance to be covered by delivery trucks are estimated in section S10 of this supplementary information and expressed as t·km and are then used to estimate the life cycle GHG emissions of the spent EV batteries transportation to EoL management facilities located in recycling clusters in Canada.
In order to estimate the environmental impact of reverse logistics of EV LIBS on total life cycle GHG emissions of battery pack recycling processing, a total life cycle carbon footprint of battery  [8]'s study provides the life cycle inventory for copper, aluminum, and steel processes recycling, and datasets are obtained from the Ecoinvent life cycle inventory database [9] to estimate the total life cycle GHG emissions for other metals recycling as 0.428 kg CO2e/kg battery pack by using OpenLCA software. Furthermore, total life cycle GHG emissions of battery cathode and battery pack production from virgin materials are estimated as 2.93 and 10.4247 kg CO2e/kg battery pack, respectively [10]. Table S9 shows the life cycle GHG emissions of recycling spent EV LIB packs including the transportation LCA results, expressed in terms of kg CO2e/kg battery pack. The environmental impact shares of recycled battery cathode materials of total life cycle GHG emissions of battery cathode and pack from virgin materials are indicated in Table S10. Regarding the transportation and collection costs, these include spent LIB transportation from end user to the collection sites and transportation costs from battery collector to dismantler and recycler. It is assumed that transportation from end user to EV scrapyards is out of the boundary in this study.
The transportation costs of spent LIBs assume truck transportation as the mode of transportation. Truck transportation on the distance greater than 110 km is assumed to be done with a heavy-duty truck (> 16t). Short-distance transportation (under 110 km) is done by medium-duty trucks (10t).
The transportation costs in this study are limited to the truck operational costs. These include diesel fuel prices, driver wages and repair and maintenance, among other costs. In this study, the truck operational costs are expressed in terms of CAD/t·km and are estimated using information from the B2U Repurposing Cost Calculator [11] and the average marginal cost for truck industry in North America report [12]. Due to a lack of available breakdowns of TDG costs, this study is only considering the handling costs for dangerous goods. Further investigation related to packaging costs for TDG needs to be accomplished. Packaging of DG needs to meet specific requirements. Non-critical and damaged battery packs must be transported in an UN-approved container, including packaging material that prevents the evolution of heat. Damaged and critical batteries require a special steel container for transportation, which includes a built-in fire extinguishing system. Additional costs to uninstall the battery from the vehicle and to package the battery into the container must be taken into consideration. It is necessary to have a certified high-voltage expert present, as the energy density is high and the battery could spontaneously combust, resulting in an immediate fire. In both scenarios, the container or package must be labelled with the UN Class 9 label for lithium-ion batteries and a UN Material Data Safety Sheet must also be filled out [1].
Transportation costs of spent LIBs have two components related to operational costs, which is distance-dependent travel cost and dangerous goods fees, if it is applicable. Hazardous materials transportation cost is related to transportation from collection sites to dismantling facilities; meanwhile, non-hazardous materials transportation cost is related to transportation from dismantling to recycling and smelter facilities. Table S11 shows the unit cost of spent LIBs transportation.  Table S 12 indicates truck transportation cost of 1 t of the spent battery packs from EV collection sites to battery processing facilities for all regional recycling clusters expressed in terms of CAD/t.